As intelligent terminals are applied in a wide range, people have a growing requirement on data traffic of a network. In order to meet people's growing network requirement and improve performance of a system, a system and a standard in a wireless local area network (WLAN) experienced evolution for multiple times. A Wi-Fi system is used as an example. A standard of the Wi-Fi system evolves successively from IEEE (Institute of Electrical and Electronics Engineers) 802.11a/b to IEEE 802.11g, IEEE 802.11n, and IEEE802.11ac.
In the standard of 802.11n, two physical-layer frame formats are defined for a data packet: an HT mixed format and an HT Greenfield format. In the standard of 802.11ac, a very high throughput (VHT) format is defined. A BPSK modulation manner is used for a signaling field of a data packet of a legacy format, a QBPSK modulation manner is used for a signaling field of a data packet of a high throughput, and BPSK and QBPSK modulation manners are used for a signaling field of a data packet of a very high throughput.
Currently, the IEEE 802.11 working group founded a High Efficiency WLAN Study Group (HEW SG). An objective of the High Efficiency WLAN Study Group is to construct a next generation wireless local area network and enhance spectral efficiency, so as to further improve a system throughput and an area throughput, thereby providing a better service for a user. The High Efficiency WLAN Study Group introduces a data packet of a new format, that is, a data packet of a HEW format.
At a receive end, signaling information of different modulation manners can be used for detection, so as to determine a corresponding format of a data packet. Therefore, which modulation manner is to be used for modulation of a signaling field of a data packet of a HEW format is a problem to be urgently resolved.